Insulating gas-tight seal.



W. E. STORY, JR.

INSULATING GAS TIGHT SEAL.

APPLICATION FILED SEPT. 19. 1914.

Witnesses:

His JTttorneg.

UNITED STATES PATENT OFFICE.

WILLIAM E. STORY, JR., 013 SCI-IENECTADY, NEW YORK, ASSIGNOR TO GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

INSULATING GAS-TIGHT SEAL.

Specification of Letters Patent.

Patented Feb. 6, 1917.

Application filed September 19, 1914. Serial No. 862,568.

To all whom z'tmay concern:

Be it known that I, "WILLIAM E. STORY, J r., a citizen of the UnitedStates, residing at Schenectady, in the county of Schenectady, State ofNew York, have invented certain new and useful Improvements inInsulating Gas-Tight Seals, of which the following is a specification.

The present invention relates to the construction of vacuum-tightinsulating seals which are of particular utility in highpowered vaporelectric devices provided with a metallic container.

One of the main difliculties experienced in this class of devices is themaintenance of a perfect gas-tight condition. of the seals at theelectrodes as the temperature variation in the course of ordinaryoperation is considerable. In a previous Patent No. 1,118,380, filed May10, 1913, I have disclosed means for reducing the variations of theanode temperature by making the anodes hollow and providing therein aquantity of mercury, which may be kept hot during periods of inaction byan electric heater. I have also shown a seal including a section ofporcelain.

A feature of my invention is the means for joining the seal to theneighboring part of the apparatus by a wall having a relatively lowthermal conductivity.

The accompanying drawing is a longitudinal section of an anode sealembodying my invention, the main part of the rectifier not having beenshown.

Referring to the drawing, the anode 1, consisting of steel, tungsten orother metal is welded to a steel tube 2, and is located within an anodearm, or side chamber 3 of the rectifier. although my invention isequally applicable to rectifier constructions in which the anode islocated in the main container. A threaded ring 4; is welded to the upperend of the tube 2 and to a tube 5 having as shown a thinner wall thanthe container proper and consisting preferably of soft steel, or othermetal of relatively low heat conductivity. A ring 6 consisting of ametal, such as nickel steel, having substantially the same coefficientof expansion as porcelain is welded to the opposite end of the tube 5,and this ring 6 adjoining a section of porcelain insulation 7 with theinterposition of suitable Washers 8 of aluminum, lead or like softmetal. Ad acent the opposite and lower side of the porcelain ring 7 isanother ring 9 of nickel steel, suitable washers 10 being here alsoused. To the ring 9 is welded a thin walled tube 11. To the opposite endof the tube 11 is welded a ring 12 consisting of iron or steel and drawnagainst the anode chamber wall 3 by means of a bolt 13 passing throughthe ring 12 and through a. ring 14. attached by screw threads orotherwise to the metal anode tube 3. Here also suitable washers 15 areused. Bearing on the nickel steel ring 6 and 9 are rings of insulation16, 17, such, for example, as a composition of asbestos and calciumsilicate described in Patent #1,009,630 to L. E. Barringer. Pressure isapplied upon the ring 16 and thus upon the seal by drawing together therings 18, 19 by bolts 20. In order to distribute the pressure squarelyupon the seal, the rings 18, 19 preferably are provided with roundedridges 21 which bear upon the center of steel rings 22, 23, these ringsin turn bearing respectively against the insulating sections 17, 16. Inorder to make the pressure continuous still springs 2-1 are preferablyinterposed between the washers 25 and the ring 18, these springs beingcompressed by tightening the nuts 26.

As described in my former application, a quantity of liquid, forexample, mercury, may be placed in the tube 2 and this may be keptheated by suitable means not illustrated and not forming a part of thepresent invention. A tube 27 has been indicated partly broken awayjoined to the anode tube and serving to condense the mercury vapor. Asteel wire 28 may be tightly bound around the porcelain to increase itsmechanical resistance to strains and prevent cracking.

The described construction prevents overheating and sudden changes oftemperature of the seal as heat from the anode tube 2 and the containerwall 3 inclosing the anode can reach the seal by conduction only througha relatively long path of poorer heat conductivity than the containerproper, afforded by the tubes 5 and 11. The resiliency of thesethin-walled tubes also reduces mechanical strains on the seal.

hat I claim as new and desire to secure by Letters Patent of the UnitedStates, is

1. The combination of a container, an electrical conductor, an insulatorinterposed between said conductor and said container and resilientmembers connecting said insulator respectively to said conductor andsaid container, said members having a lower heat conductivity than saidcontainer.

2. The combination of a container, an electrical conductor, a ring ofmineral insulation interposed between said conductor and said container,metal rings adjoining said mineral ring, Washers interposed respectivelybetween said mineral ring and each of said metal rings, tubes ofresilient material having thinner Walls than said container and a.relatively low heat conductivity joined respectively one to a metal ringand the container, and another to a metal ring my hand this 18th day ofSeptember 1914:. 20:

WILLIAM E. STORY, J R. \Vitnesses:

BENJAMIN B. HULL, BENJ. H. VVEISBROD.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

I Washington, D. C.

